An in-cell touch panel is a device that integrates a touch panel and a display screen. The touch driving electrode and the touch sensing electrode are integrated in the display screen to implement touch and image display functions at the same time. In-cell touch panels have gradually become the main stream in display field due to their simple, light and thin structure and low costs.
Referring to FIG. 1, FIG. 1 shows transversely disposed touch driving electrodes 800 and longitudinally disposed touch sensing electrodes 900. Coupling between adjacent touch driving electrode 800 and touch sensing electrode 900 generates a mutual capacitance Cm. When a finger touches the screen, the touch of finger would change the value of said mutual capacitance Cm. A touch detection device detects the location of finger touch point by detecting the current change of the capacitance Cm before and after touch.
In an in-cell touch panel, in order to improve the touch effect of the touch panel, touch driving electrodes and touch sensing electrodes have large areas, therefore touch signals will interfere with image display signals. At the same time, image display signals will interfere with touch signals too. Furthermore, touch driving electrodes and touch sensing electrodes with large areas would reduce opening ratio of a touch panel.